Someone can help me? its about AC2

i hve been playing assasins creed 2 and after play 1 day the game start to freeze and the screen goes black, and then back to the game. Finally again the screen goes black and crash. Appears the dekstop.Idont know what is happening but if someone can help me it will be very good. I hve reinstalled the game and i play well but after 1 day starts the problems again. Today happened and i reinstalled the game but directly the game turns in black screen.I think im in the half of the game cuz im in Venice now. So who can help me?